Help:Using old PrimePages data

For the place-holder dates prior to about 1996 for prime submissions at top-5000, they have been handled as follows:

1. If the date is Jan. 1st, show only the prior year with no month or day, i.e. 1/1/1990 are shown here as 1989.
2. If the date is the 1st of some other month, show the year and month of the previous month, i.e. 3/1/1993 is shown here as 1993-02 with no day shown.

A date can usually be identified as a place-holder if the date falls on the 1st of the month and the time is 4:59:59 or 5:59:59. All/most of the old dates/times were entered in CST (U.S. Central time zone) as the last day, minute, and second of the month/year in which they were discovered, i.e. local time of 23:59:59. When PrimeGrid took over management of the site, all of the times were converted to UTC. This had the effect of adding 5 or 6 hours to them depending on CST daylight saving time on the date of the original submission resulting in all dates shown now as the 1st of the month.

Gary Barnes (talk) 12:57, 24 June 2024 (UTC)
edit Gary Barnes (talk) 05:54, 26 June 2024 (UTC)